Device for dispensing a liquid-to-pasty product using a metering pump having a low dead volume

ABSTRACT

A device for dispensing a liquid-to-pasty product to be placed at the open end of a rigid container and consisting of a manual metering pump for dispensing a predetermined amount of the product to be dispensed, includes a base member to be placed on the container, a push button provided with a dispensing spout capable of acting, when pumped, against an intermediate bellows comprising an opening/closing device provided at the upper end of the bellows, characterized in that the push button is combined with a cylindrical chamber directed towards the inside of the bellows and extending inside the bellows so as to form a dead volume with a predetermined value inside same and to accordingly reduce the available air volume, thereby improving the compression rate when pumped.

BACKGROUND

This invention relates to a device for dispensing a liquid-to-pastyproduct intended to be installed at the open end of a rigid container,and constituted by a manual metering pump making it possible to dispensea predetermined quantity of the product to be dispensed.

Such pumps are in particular intended for the dispensing of allliquid-to-pasty products, whether pertaining for example to food,cosmetic products, hygiene, health, and beauty products or sun products.

But from the moment the pumps were positioned on markets with lowervalue added, such as food or cosmetics, hygiene, health and beauty, thecomplexity and the price of the pumps have constituted a hindrance.

Most of these new products that use these pumps are disposable products,with a reduced service life. In addition, their requirements in terms ofdose precision and repeatability are more reduced.

This problem with simplification has appeared very recently with thedemocratization of products, initially high-end, to be adapted for massdistribution.

It is as such that the creation of a pump dispensing system having fewparts has already been sought, in any case with the least amount of partpossible, in such a way as to make it economical.

A device aiming to achieve this objective was described in French patentapplication Ser. No. 07/02965 filed by the applicant, which in addition,resolved a safety problem on the dispensing of the product, with thelatter no longer able to occur accidentally.

The results obtained, even if they are satisfactory, can be furtherimproved concerning the priming of the pump.

In fact, the main disadvantage of this pump is its substantial deadvolume associated with a low compression rate. Indeed, tests have shownthat only 37% of its metering chamber is compressed when the push buttonis pressed. In the priming phase, the air contained in the meteringchamber and the dip tube must be evacuated, by compressing the air ofthe metering chamber and to force it to pass through a high valve.

With such a low compression rate of the air in the metering chamber, theair has difficulty reaching the pressure required to pass through a topvalve of the device and the operation is not effective. This results inpriming that is too long due to the requirement of having to exertseveral presses on the push button.

This can be explained by the fact that the volume of air, whichcorresponds to the volume of the bellows, generates the priming phase ofthe pump when the air is compressed, during the actuating of the pushbutton.

Recall that the priming is carried out in the following manner:

The push button is pressed in order to compress the air inside thebellows, and this air will escape via the top valve, until a stabilizingpressure is reached.

During the release of the bellows, the push button rises up and createsa vacuum in the metering chamber corresponding to the volume of escapedair.

This vacuum generates a suction of the product via the bottom valve ofthe same device.

This operation is currently repeated too many times given thesubstantial volume of air to be actuated in relation to useful volume(dose) of the product dispensed, several times higher than this dose.

For example, for a chamber volume of the bellows equal to 4.07 ml, acompression of 37% of this volume is obtained, allowing for thedispensing of a dose of 1.5 ml.

In this case, the initial compression of the air is 600 mbars, and thevacuum generated is 370 mbars.

All of this results in a dead volume equal to 4.07 ml−1.5 ml≈2.5 ml,therefore 63% of the non-effective initial volume during the priming.

This therefore generates a substantial loss of effectiveness, resultingin a substantial number of pumpings: about twelve priming strokes.

SUMMARY OF THE INVENTION

It is as such that according to a first phase of the inventive approach,it was established that it is required to reduce the dead volume in thebellows.

For this, and according to the invention, a dead volume reducer calledsolid volume is installed inside the bellows, in an integral manner withthe push button, occupying a determined volume inside the bellows,allowing a useful volume of air to subsist corresponding to at least thevolume of one dose of the product.

As such, a gain is made in the effectiveness in the priming phase inorder to evacuate the air. The quantity of air that passes through thetop valve is higher, and therefore a volume of product that is higher issucked to replace the air evacuated via the top valve, and thereforehave faster priming.

This invention has for purpose to achieve this objective and relates tothis effect to a device for dispensing a liquid-to-pasty productintended to be installed at the open end of a rigid container andconstituted by a manual metering pump allowing for the dispensing of apredetermined quantity of the product to be dispensed, comprising:

a base member intended to be installed on the container by its lower endvia a means of hooking or of adhesion such as clipping or screwing,

a push button provided with a dispensing spout mounted in a telescopicmanner at the upper portion of the base member and able to act inpumping in relation to the latter, counter to a retaining memberconstituted by

an elastically deformable bellows providing the sealed link between onthe one hand an internal chamber of the base member, opened towards thecontainer in order to allow for the passage of the product through anopening, and on the other hand, at its upper end, an internal chamber ofthe push button wherein exits a hole of the dispensing spout, associatedwith opening/closing means, made at the upper end of said bellows,

characterized in that the push button is associated with a cylindricalchamber, directed towards the interior of the bellows with whichcooperates, in a sealed manner, a peripheral wall delimiting saidchamber, the latter being hermetically sealed at its lower internal endand extending to the interior of the bellows, in order to constitute asolid volume of predetermined value inside the latter and reduce by asmuch its useless dead volume, improving as such the compression ratewhen pumped and the effectiveness of the pump.

Thanks to the invention, the results obtained, compared to the previousresults, are as follows, for the same bellows with a dead volume reducerarranged inside the latter.

For a new chamber volume of the bellows reduced to 2.56 ml, a newcompression of 62% of this volume is obtained, making it possible todispense an identical dose of 1.5 ml.

In this case, the initial compression of the air is now 1350 mbars andthe vacuum generated is 570 mbars. According to the effect sought, thischanges from twelve priming strokes, according to prior art, to sixpriming strokes, which is half less.

In addition, the invention allows for the use of products with a higherviscosity due to the fact that the pressure and the suction are alsohigher.

The invention also relates to the characteristics that will appear whenreading the following description, and which must be consideredseparately or according to all of their possible technical combinations.

BRIEF DESCRIPTION OF THE DRAWINGS

This description provided by way of a non-restricted example, shallallow for a better understanding of how the invention can be carried outin reference to the annexed drawings wherein:

FIG. 1 shows a longitudinal cross-section view of a dispensing pumpaccording to the invention, arranged on a containing of a product to bedispensed, the push button being in the “before use” position.

FIG. 2 shows a longitudinal cross-section view of a dispensing pump ofFIG. 1, in a first priming phase of the pump, i.e. with the push buttonbeing pressed.

FIG. 3 shows a longitudinal cross-section view of a dispensing pumpaccording to FIG. 2, in a second priming phase of the pump, i.e. duringthe rising of the push button, having for effect to raise the liquid inthe chamber constituted by the bellows.

FIG. 4 shows a longitudinal cross-section view of a dispensing pumpaccording to FIGS. 1 and 3, during a dispensing of the product, bypressing once again the push button downwards.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

The device 1 globally designated in the figures is intended for thedispensing of a liquid-to-pasty product 2, installed at the open end 3of a rigid container 4, and is constituted by a manual metering pump 5,allowing for the dispensing of a predetermined quantity of the product 2to be dispensed.

In a known manner, the device 1 comprises:

a base member 6 intended to be installed by a means of hooking or ofadhesion such as clipping or screwing on the container 4 by its lowerend 7,

a push button 8 provided with a dispensing spout 9 mounted in atelescopic manner at the upper portion 10 of the base member 6 and ableto act in pumping in relation to the latter, counter to a retainingmember constituted by

an elastically deformable bellows 11 providing the sealed link betweenon the one hand an internal chamber 12 of the base member 6, openedtowards the container 4 in order to allow for the passage of the product2 through an opening 13, and on the other hand, at its upper end, aninternal chamber 14 of the push button 8 wherein exits a hole 15 of thedispensing spout 9, associated with opening/closing means, made at theupper end of said bellows 11.

These means are comprised of:

a first internal peripheral collar 16 made at the upper end of thebellows 11, being housed in an internal annular groove 14 of the pushbutton 8 forming a chamber, and pressing against one of its internalwalls 17 that it tightens elastically according to a predeterminedforce, in such a way as to provide the seal or to be deformed radiallyunder a certain pressure of the product 2 when it is pumped, and as suchallow it to be transferred into the annular groove 14, said first flange16 being associated with

a second collar 18 of the bellows 11, concentric to the first 16, beinghoused in the same groove 14 of the push button 8, but pressing againstthe external wall 19 of the latter wherein groove 14 exits from theorifice 15 of the dispensing spout 9, said second collar 18 being of aheight such that it does not obstruct said orifice 15, the opening orthe closing of the latter being carried out by the intermediary of alocking tab (not shown), coming from the flange 18, of height and ofwidth at least such as to obstruct the orifice 15 by thrusting against,or to release it during an action in rotation, in one direction or inthe other, on said push button 8, in relation to the base member 6, andconsequently to the bellows 11, and to its tab, remaining fixed.

According to the invention, the push button 8 is associated with acylindrical chamber 8A, directed towards the inside of the bellows 11with which cooperates, in a sealed manner, a peripheral wall 17delimiting said chamber 8A, the latter being hermetically sealed at itslower internal end and extending into the interior of the bellows 11, inorder to constitute a solid volume of predetermined value inside thelatter and reduce by as much its useless dead volume, as such improvingthe compression rate when pumped and the effectiveness of the pump.

According to a preferred embodiment, the chamber 8A constituting thesolid volume inside the bellows 11 is carried out in two members, ofwhich one is constituted by an internal extension 8B of the push button8, open at its lower end “b”, and the other is constituted by an insert8C which is globally cylindrical, closed at its lower end portion “a”and open at its upper end portion “c”, with the latter being added onthe lower open portion “b” of the first member 8B in order to constitutethe solid volume 8A.

This indeed entails a dead volume reducer according to the effect soughtby the invention.

According to a particular embodiment, the insert 8C has an upper portion“d” of which the external shape and dimension correspond, to the nearbyassembly clearance, to the internal shape and dimension of the lowerportion “e” of the extension 8B of the push button 8 whereon is addedthe insert 8C.

The effective connection between the insert 8C and the extension 8B ofthe push button 8, in their respective end zones, is carried out bygluing, by force fitting or by ultrasonic welding.

Indeed, the dimensions of the chamber 8A are calculated according to thereduction in volume of the bellows 11 to be obtained, and consequently,of the compression rate sought. For this, action is preferentially takenon the dimensions of the insert 8A which is in fact a removable member.

As can be understood, the bellows 11 and the insert 8C, both of globallycylindrical shape, delimit between them a concentric crown-shaped volume20, and the product 2 transits via this crown.

As can be seen in the figures, the upper end portion “c” of the insert8C is delimited, on its external wall, by a peripheral shoulder 21whereon abuts the end edge “b” of the lower portion of the extension 8B.

Advantageously, the various parts of the system are made from plasticmaterials.

Advantageously, the bellows is made of a plastic material, morepreferably elastically deformable.

Advantageously, the material comprising the bellows has a highelasticity and is at the same time able to provide, between the two casemembers, the retaining forces required for the pumping. It is as suchthat the choice was directed towards a plastic material that issufficiently flexible in order to provide a good seal on flanges,sufficiently responsive in order to provide a return to the initialposition and provide a vacuum, and sufficiently resistant to creeping inorder to make it possible to retain the initial tightening as well asretain a repeatability of compression travel and therefore of the dose.

Preferentially, the bellows is made from an injection molding oflow-density polyethylene.

Also, SANTOPRENE (Polypropylene-modified Ethylene Propylene DieneRubber), or HYTREL (Thermoplastic Elastomer-Ether-Ester, DRYFLEX(Styrene-Ethylene-Butylene-Styrene Styrenic Thermoplastic) could beused, materials that did not exist about twenty years ago, as well ascertain references for polyethylenes that are created or modified inorder to guarantee responsiveness and acceptable resistance to creeping.

These names are commercial names, the chemical names are in parentheses.

These materials have all of the aforementioned characteristics.

As can be easily seen in FIGS. 2, 3 and 4, the operation of the deviceis as follows:

During the first use, a press is exerted on the push button 8 accordingto the direction F1, i.e. downwards, having for effect to flush, via thespout 15, the air which is located in the bellows 11.

By releasing the pressure F1 on the push button 8, that latter risesnaturally according to the direction F2, drawing the product 2 upwards,partially filling the internal volume of the bellows 11.

During a another press in the direction F3, i.e. downwards, exerted onthe push button 8, a pressure will be exerted no longer on the airlocated in the bellows 11, which has already been evacuated, but on theproduct 2 which will be flushed by the concentric space 20 createdbetween the insert 8A and said bellows 11, for a faster evacuation ofthe product via the spout 15 of the push button 8, and this with anumber of presses on the latter also reduced, for an improvedeffectiveness in the dispensing of the product.

More precisely, the evacuation of the product is carried out bytransiting in a concentric crown-shaped volume 20 formed by the exteriorwall of the cylindrical chamber 8A and the bellows 11.

1-5. (canceled)
 6. Device for dispensing a liquid-to-pasty productintended to be installed at an open end of a rigid container andconstituted by a manual metering pump allowing for the dispensing of apredetermined quantity of the product comprising: a base member intendedto be installed on the rigid container by a lower end via at least oneof hooking, adhesion, clipping, and screwing, a push button providedwith a dispensing spout mounted in a telescopic manner at an upperportion of the base member and able to act in pumping in relation to thebase member, counter to a retaining member constituted by an elasticallydeformable bellows providing a sealed link between an internal chamberof the base member, opened towards the rigid container in order to allowthe passage of the product through an opening, and at an upper end, aninternal chamber of the push button wherein exits a hole of thedispensing spout, associated with opening/closing means, made at theupper end of said bellows, the push button is associated with acylindrical chamber, directed towards the interior of the bellows withwhich cooperates, in a sealed manner, a peripheral wall delimiting saidcylindrical chamber, and the cylindrical chamber being hermeticallysealed at a lower internal end and extending to the interior of thebellows in order to constitute a solid volume of predetermined valueinside the bellows and reduce by as much useless dead volume, improvingas such a compression rate when pumped and the effectiveness of thepump.
 7. Device according to claim 6, wherein the cylindrical chamberconstituting the solid volume inside the bellows is carried out in twomembers, of which one is constituted by an internal extension of thepush button, open at a lower end, and the other is constituted by aglobally cylindrical insert, closed at a lower end portion and open atan upper end portion, with the insert being added on the lower openportion of the first member in order to comprise the solid volume. 8.Device according to claim 7, wherein the insert has an upper portion ofwhich an external shape and dimension correspond, to a nearby assemblyclearance, to the internal shape and dimension of the lower portion ofthe extension of the push button whereon is added the insert.
 9. Deviceaccording to claim 8, wherein the upper end portion of the insert isdelimited, on an external wall, by a peripheral shoulder whereon abutsan end edge of the lower portion of the extension.
 10. Device accordingto claim 6, wherein evacuation of the product is carried out bytransiting in a concentric crown-shaped volume formed by the exteriorwall of the cylindrical chamber and the bellows.